The HID lenovo probe function only attaches drvdata to one of the
USB interfaces, but lenovo_event() will get called for all USB interfaces
to which hid-lenovo is bound.
This allows a malicious device to fake being a device handled by
hid-lenovo, which generates events for which lenovo_event() has
special handling (and thus dereferences hid_get_drvdata()) on another
interface triggering a NULL pointer exception.
Add a check for hid_get_drvdata() returning NULL, avoiding this
possible NULL pointer exception.
Fixes:
bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support")
Reviewed-by: Marek BehĂșn <kabel@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
static int lenovo_event(struct hid_device *hdev, struct hid_field *field,
struct hid_usage *usage, __s32 value)
{
+ if (!hid_get_drvdata(hdev))
+ return 0;
+
switch (hdev->product) {
case USB_DEVICE_ID_LENOVO_CUSBKBD:
case USB_DEVICE_ID_LENOVO_CBTKBD: